Do Cataracts Cause Complete Blindness?

All kinds of reasons such as aging, heredity, local nutritional disorders, immune and metabolic abnormalities, trauma, poisoning, radiation, etc. can cause lens metabolism disorders, resulting in lens protein degeneration and turbidity, which is called cataracts. Interference cannot be projected on the retina, resulting in blurred vision. More common in people over 40 years of age, and the incidence increases with age.

Basic Information

English name: cataract
Visiting department: Ophthalmology
Multiple groups: 40 years and over

Common causes: Related to genetics, immune and metabolic abnormalities, trauma, poisoning, etc.
Common symptoms: Blurred vision, fear of light, dark or yellowish color

Causes of cataract

All kinds of causes such as aging, heredity, local nutritional disorders, immune and metabolic abnormalities, trauma, poisoning, radiation, etc. can cause lens metabolism disorders, cause lens protein degeneration and turbidity, and lead to cataracts. The disease can be divided into congenital and acquired:

Congenital cataract

It is also called developmental cataract. It usually exists before and after birth. It is mostly static and can be accompanied by genetic diseases. There are two types of endogenous and exogenous. Endogenous is related to fetal developmental disorders. Exogenous is maternal or Fetal systemic lesions are caused by damage to the lens. Congenital cataracts are divided into anterior cataract, posterior cataract, nuclear cataract, and total cataract.

2. Acquired cataract

Lens opacity due to systemic or local eye disease, abnormal nutritional metabolism, poisoning, degeneration, and trauma after birth is divided into 6 types: senile cataract, the most common, also known as age-related cataract, more common in 40 years old The above, and increase with age, are related to multiple factors, such as the slow metabolism of the elderly and the occurrence of degenerative diseases, and some people think that it is related to long-term sunlight exposure, endocrine disorders, metabolic disorders and other factors. There are two major types of nuclear and cortical. complicated cataract (complicated with other eye diseases). Traumatic cataract. Metabolic cataract. radiation cataract. Drugs and toxic cataracts.

Clinical manifestations of cataract

Unilateral or bilateral, the onset of both eyes may be progressive, progressive vision loss, different refractive power of different parts of the lens due to opacity of the crystal cortex, glare, or monocular diplopia, increased myopia, clinically divided senile cataract There are three types of cortical, nuclear and subcapsular.

Cortical cataract

It is characterized by grayish white turbidity of the crystal cortex, and its development process can be divided into four stages: initial stage, immature stage, mature stage, and mature stage.

2. Nuclear cataract

Crystal turbidity begins to increase in density from the center of the lens, that is, the position of the embryo's nucleus, and gradually increases and slowly expands to the surroundings. It appears pale yellow in the early stage. As the turbidity increases, the color gradually deepens like dark yellow, dark brown, and the density of the nucleus increases. Refractive index increases. Patients often report reduced presbyopia or increased nearsightedness. The peripheral cortex is still transparent in the early stages. Therefore, the dilated pupils in the dark place have improved vision, but the pupils have reduced vision in strong light, so they generally do not wait for the cortex. Complete turbidity and surgery.

3. Cataract under the posterior capsule

The opacity is located in the subcapsular cortex of the lens. If it is located in the optic axis area, it affects vision early.

Cataract examination

You should know whether the vitreous, retina, macular region of the optic papilla and optic nerve are normal and whether there is choroidal lesions. The vision recovery after cataract surgery will be correctly evaluated. You can use type A and B ultrasound to understand whether there are vitreous lesions, retinal detachment or eyes. Internal tumors can also understand the length of the axis of the eye and the position of the dislocated lens. Electroretinogram (ERG) is of great value in evaluating retinal function. Patients with monocular cataracts can be used as evoked potentials to rule out visual impairment caused by macular pathological disorders (VEP) examination, and macular function of immature cataracts can also be examined with a vision interferometer.

Cataract diagnosis

From the perspective of group blindness prevention and blindness control, the World Health Organization degenerates and opacifies the lens, becomes opaque, and even affects vision. Correction of vision is 0.7 or below to diagnose cataract.

Cataract Treatment

Drug treatment

At present, both at home and abroad are at the stage of exploration and research. Some early cataracts will slow down and develop vision after clinical use, and vision will be slightly improved. The early progress to maturity of cataracts is a long process, and it may stop naturally in a certain development. Stage without seriously affecting vision. Early cataract can be taken orally with vitamin C, vitamin B2, vitamin E, etc., and some drugs can be used to delay the development of the disease. Usually in some patients with intermediate cataracts, vision and opacity of the lens can be improved to some extent. However, in mature cataracts, drug treatment has no practical significance.

2. Surgical treatment

(1) cataract phacoemulsification is a new type of cataract surgery developed in recent years at home and abroad. The nucleus of the lens is pulverized using ultrasound to form a chyle, and then sucked out together with the cortex. After the operation, the posterior capsule of the lens is retained, and the intraocular lens can be implanted simultaneously. Senile cataracts develop to a vision below 0.3, or the degree and location of cataracts significantly affect or interfere with visual function. Patients who want good visual quality can perform phacoemulsification cataract surgery. Its advantages are small incision, less tissue damage, short operation time, and fast vision recovery.

(2) Extracapsular cataract extraction The incision is smaller than the intracapsular extraction. The cloudy lens nucleus is discharged and the cortex is aspirated, but the posterior lens capsule is left. The posterior capsule is retained and can be implanted into the posterior chamber intraocular lens at the same time, and the visual function can be restored immediately after operation. Therefore, extracapsular cataract extraction has become a conventional surgical method for cataract.

Cataract prognosis

Patients who master the indications for surgery, choose the correct surgical method, and reduce complications during and after surgery have a good prognosis. The patient returns to normal visual function after anti-inflammatory treatment. Avoid violent remote movements, and especially avoid collision injuries to the eyes and the head around the eyes. After 3 months, some patients need optometry, and there are residual refractive errors that require optician correction.